Advice on Head Studs for 930

[SteveCarr]

Hi there, I am rebuilding my 1985 930 Turbo and wanted some advice and tips about what cylinder head studs I should use when I re-assemble.

I am not planning to increase the engines power from stock and as such I don't really want to spend too much on studs, nuts and washers.

I don't think it is a good idea to use diliver studs after reading Waynes book so would standard steel studs be OK or would it be wiser to use a set of the aftermarket studs such as ARP or Raceware?

Also does anybody have any good advice as to where I can purchase from in the UK.

Any tips or advice would be gratefully received.

Many thanks

Steve in the sunny UK!

[Henry Schmidt]

There are no better studs on the planet than Supertec.
Not only are they made from a far superior material but they have a unique design not available in any other head stud kit. Tested to 800 hp 1600lb cylinder pressure.
Top quality, unIque design and reasonable price for a superior design WITH A LIFE TIME WARRANTY.
They are available from Pelican Parts.

[SteveCarr]

Hi Henry and thanks for your advice I appreciate it.

Is it really necessary to fit such excellent studs on a stock engine?
Could I possibly use something cheaper and still get acceptable results?

I don't plan to race the car just use it on the road.

Best regards

Steve

[Henry Schmidt]

You asked about ARP and Raceware. Supertec studs are better and less expensive.
Can you get away with something cheaper ? Sure
The question is , where do you want to cut corners ?

When engine components shuffle around there can't help but be increased wear and loss of performance. Nothing we've tested holds the cylinders and heads in place better that Supertec studs.
Engine integrity starts with first quality hardware.

[DonE]

There are two areas, at minimum, you don't cut corners on with a turbo motor rebuild- head studs and rod bolts. Even for road usage...

[Carrera3.5L]

Originally posted by Henry Schmidt
Top quality, unIque design and reasonable price for a superior design WITH A LIFE TIME WARRANTY.

[/B]

I don't want to start an "incident" since you sometimes are chippy on this site when people don't agree or question you, but you are constantly touting a "lifetime warranty" on your head studs. But what does your "lifetime warranty" actually cover? Lifetime warranty can mean different things to different people.

Does it simply cover a replacement stud in the unlikely event it were to break or does it also cover the replacement parts and/or labor to tear the motor down to the point where the stud can be replaced?

If the former, in all honesty the warranty means little to nothing (the price of a single stud shouldn't kill anyone on this board) and is simply marketing hype but if the latter than that is great and commendable on your part and should certainly lead to increased sales I would think.

Any explanation on your part would be greatly appreciated as I'm sure other people are probably wondering the same thing and are too afraid to ask and risk your ire. Me, I don't care.

Ralph

[Henry Schmidt]

The warranty simply states that if any stud fails for any reason the stud will be replaced. The term "life time" is simply meant to state that there is no time limit.

I'm sorry if you find this guarantee to have no value. The reason I find it valuable is that many people are rebuilding their engine simply because their studs broke. We were hoping the warranty would help put our customers or potential customers mind at ease. They will not break, ever! You have my word on it.
I believe that has some value.

I would wonder why you are not challenging the ARP ad that clearly states "fine threads at the head end of the stud for more accurate torquing" which is absolutely false. Their studs have 10x1.50 threads at both ends.
OR
The Raceware ad that also states "life time warranty".

http://www.pelicanparts.com/catalog/shopcart/911M/POR_911M_ENGpis_pg5.htm#item16

One last thought. How valuable would it have been if in 1978 Porsche used Supertec studs? How many more 911SC, 930 Turbos would have made it to 250K mikes?

[Henry Schmidt]

Originally posted by Carrera3.5L
I don't want to start an "incident" since you sometimes are chippy............................................ ............... I'm sure other people are probably wondering the same thing and are too afraid to ask and risk your ire. Me, I don't care.

Ralph

The wrath of Henry, wow maybe they'll make a movie.

I am aware that in this "politically correct, free to be you and me, hug a tree" world that some people live in, that it is not popular to state a position you believe in then stand behind it.

I was not raised that way. I state what I believe (as clearly as possible) and defend it passionately.
The truth is, not all opinions carry the same expertise and experience has value.

If my passion has offended some of you that is/was not my intention. Disseminating accurate information and dispelling false conclusions is.

[cgarr]

I thought the reason for fine thread was they are less susceptible to backing off,

[Henry Schmidt]

You're correct in that a fine thread nut or bolt requires less torque to remain tight.

[Carrera3.5L]

Originally posted by Henry Schmidt
The warranty simply states that if any stud fails for any reason the stud will be replaced. The term "life time" is simply meant to state that there is no time limit.

I'm sorry if you find this guarantee to have no value. The reason I find it valuable is that many people are rebuilding their engine simply because their studs broke. We were hoping the warranty would help put our customers or potential customers mind at ease. They will not break, ever! You have my word on it.
I believe that has some value.

I would wonder why you are not challenging the ARP ad that clearly states "fine threads at the head end of the stud for more accurate torquing" which is absolutely false. Their studs have 10x1.50 threads at both ends.
OR
The Raceware ad that also states "life time warranty".

http://www.pelicanparts.com/catalog/shopcart/911M/POR_911M_ENGpis_pg5.htm#item16

One last thought. How valuable would it have been if in 1978 Porsche used Supertec studs? How many more 911SC, 930 Turbos would have made it to 250K mikes?

Thanks for the clarification, I will be honest and say the warranty means absolutely zilch to me. If ARP & Raceware offer the same warranty, it is useless to me as well. The reason why it has no value to me personally is simply because of the thousands of dollars it would potentially cost in parts/labor to fix a broken stud, the cost of an individual stud or studs is a drop in the bucket. For Supertec or one of the "other guys" to simply replace a $20 (or whatever a single cost stud costs) stud when one would have to spend thousands to replace it wouldn't lift my spirits much. Just stating my personal opinion, have no idea as to whether it is shared by others or not...

You probably know this but many others probably don't that ARP used to make Raceware's product when they first started out. Raceware was simply ARP rebranded. They split up many years ago with a nasty divorce...

If ARP's technical information is indeed incorrect, shame on them and they should change it. I would certainly say something if they post on this forum, but they don't to the best of my knowledge. I do know a fairly high-ranking guy in their engineering dept, I will shoot him an email and ask for clarification and perhaps he can write a note to their marketing dept to change the info if incorrect when they print their new catalog?

The only reason why I brought this whole issue up is not to disparage you or your product, but simply clarify what the lifetime warranty actually means. I don't believe that it has ever been discussed in prior threads so now everyone knows what it entails and can form their own opinions as to individual value...

As to how valuable an aftermarket stud such as Supertec, ARP, Raceware, Performance Developments, insert aftermarket name here would have been to SC & 930 engine longevity, well hindsight is always 20/20.

You may know who Jo Hoppen was/is, one of his favorite sayings was "you catch flies with honey" and I'll simply leave it at that.

Ralph

[Steve@Rennsport]

Great thread!

Thanks for your contributions Ralph, as I share your views about warranties, especially in this case. They are not worth anything to me: all I want are good, reliable parts.

We've had plenty of issues with loose head nuts on ARP studs (especially on turbo cars) so we no longer use them. Metallurgically speaking, I think they are good parts but the failure to stay tight is unacceptable to me.

We've had excellent success using either factory steel in small motors or GT-2 dilavar studs in bigger/or turbocharged ones without a failure (knock wood) and no loose heads. Some of these are high compression (14:1+) engines turning over 8K and some are boosted over 1.2 bar.

I've not tried Henry's headstuds nor Performance Development's but thats certainly an option for the future if that becomes necessary.

This has been an excellent discourse and I do wish that Neil Harvey had time to ring in here on this.

[Henry Schmidt]

Steve : At this point some 5 years we have never seen a loose head nut issue on na, turbo or high performance race engines. Knock on wood.


Ralph : The next time I want to catch flies, I'll rely on your expertise.

Thank you both

[boba]

Originally posted by Carrera3.5L


You may know who Jo Hoppen was/is, one of his favorite sayings was "you catch flies with honey" and I'll simply leave it at that.

Ralph

I think I first met Jo in 1977 and that may have been one of his favorite sayings but I don't remember that behavior.

[Steve@Rennsport]

Originally posted by Henry Schmidt
Steve : At this point some 5 years we have never seen a loose head nut issue on na, turbo or high performance race engines. Knock on wood.

Good to hear and I'll keep you in mind on those things,...

[Carrera3.5L]

Hi Henry (and everyone else reading):

As promised, I inquired and received some info from ARP regarding their 911 stud (though not from my normal contact who is on his way to Hockenheim for the F1 race this weekend). Here are the specifications as quoted:

6.750" overall length
M10 x 1.5 x 1.050" on case end
M10 x 1.5 x 0.640" on head end with a .310" nut starting nose
Stud is Inconel 718, 220 ksi minimum

Nowhere on their website or 2006 catalog could I find anything that referenced about the head end of the stud being fine threaded as you mentioned earlier. Unless I misunderstand, I think your quote was taken from Pelican's own marketing of the product and probably shouldn't be held against ARP as false advertising. You can't definitively control what is said in someone else's marketing materials about your products, can you?

I don't know anyone at Raceware and don't know if they would release their specifications. I had bad experiences with Raceware products many, many years ago and would rather avoid them. If anyone is further interested and wants to call Raceware themselves...

Interesting Steve with your comments regarding Neil, he called me yesterday afternoon because apparently one of his customers who is watching this thread called him in the morning and said his name was mentioned. He's not into the whole internet forums thing to begin with and is knee deep in a vintage 956 engine rebuild and doesn't have the time anyway but he just wanted to know what was going on.

I won't speak for him entirely, but his basic opinion is that most of the aftermarket head studs are more than adequate in material composition and that the biggest factor for long-term success is the installation itself. He believes (to a certain extent) that an "inferior" (relative term) aftermarket stud installed properly will still be better than the trickest, zoomiest stud that is installed incorrectly and that is where many of the problems lie. Of course, you can't beat a trick, zoomy stud installed properly!

If you know Neil's pedigree, his work & projects are very high level & top notch and he is not trying to be the cheapest around. His clientele recognizes high-quality when they see it and are willing to pay for it. If anyone has questions regarding his head studs or philosophy regarding them he is happy to speak with you.

Regarding Jo, the following quote can't be attributed to him but certainly applies to him "Do as I say, not as I do"

Ralph

Ralph

[SteveCarr]

Out of interest where is the best place (cheapest) to buy ARP studs in the USA? Do you know if there is a supplier in the UK?

Best regards

Steve

[Carrera3.5L]

Originally posted by SteveCarr
Out of interest where is the best place (cheapest) to buy ARP studs in the USA? Do you know if there is a supplier in the UK?

Best regards

Steve

Steve,

I have no idea where the cheapest place is and whether any potential savings is even worth taking the time to poke around.

If you have your heart set on ARP's, why not purchase from Pelican? They broker this BBS and while I'm not sure, I would assume that they have the capability to ship worldwide (what mailorder company doesn't?)

If they don't, here is a list from ARP's site of European distributors:

http://www.arp-bolts.com/Images/ARP_EU_Distributors.pdf

Pelican also seems to offer most of the aftermarket head studs to meet the wishes of any consumer. You can put Henry's in the mix (he's provided all the info on his product) and Raceware (whose remain a mystery). The only other major player that doesn't seem to be on their site is Neil's and chances are they have no idea who he even is...

Talk to Henry, talk to ARP and talk to Raceware and determine who you feel most comfortable with...

Ralph

[Jeff Alton]

This is a good thread.... good techinical content and a few good opinions as well! I agree with Ralph about the warranty issue. As a side not while doing an inspecion today a gentlemen from a new radiator shop happened by to shop his wares. They have a parts and LABOUR warranty on their products. Once he left the vehicle owner and I both looked at each other and said "they should be out of business with that warranty soon!" I guess if one really stands behind their product as the absoulute best they could afford to make that type of warranty available......

Cheers

[rotorhead]

Originally posted by SteveCarr
Hi there, I am rebuilding my 1985 930 Turbo and wanted some advice and tips about what cylinder head studs I should use when I re-assemble.

I am not planning to increase the engines power from stock and as such I don't really want to spend too much on studs, nuts and washers........

.... Is it really necessary to fit such excellent studs on a stock engine?Could I possibly use something cheaper and still get acceptable results?.........

Any tips or advice would be gratefully received.

Many thanks

Steve in the sunny UK!

Steve, I faced the same questions a while back and decided to replace my Dilivar Studs with stock steel studs.

It was a compromise but all the information I was able to gather indicated that the steel studs were appropriate for my engine remaining at stock boost levels and delivering <400hp.

I believe that the stock steel studs won't break like dlivar but at higher hp other factors like head blowby and relaxing clamping force have been observed.

Henry and Steve, are experts and everything they have said is perfectly true.

My research on the board shows that there are three separate camps on the issue of 930 head studs.

1. Those who say hang the expense and put the ARP/Raceware/Supertec stud in and do it properly .

2. Those who say the 930 motor gets a lot hotter and the Dilivar is the best stud for that engine regardless of corrosion issues, and

3. Those who say the original 911 steel studs will suffice (there may be issues using the 993 steel studs) on mostly stock motors.
(see the picture posted by DonE here )



Steve